Mainspring for watches



2 Sheets-Sheet 1.

(No Model.)

J. B. JOBSON, MAINSPRING POR WATCHES.

No. 497,429. Patented May 16,1893.

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(No Model.) 2 Sheets-Sheet 2.

J. B. JOBSON. MAINSPRING POR WATCHES.

No. 497,429. Patented May 16,1893.

UNITEDY STATES PATENT OEEicEo JOHN B. JOBSON, OF MACON, GEORGIA.

MAINSPRING FOR WATCHES.

SPECIFICATION forming part of Letters Patent N o. 497,429, dated May 16,1893.

Application iiled August 9, 1892. Serial No. 442,561. (No model.)

T0 all whom t may concern:

Be it known that I, JOHN B. JOBsON, a citizen of the United States,residing at Macon, in the county of Bibb and State of Georgia, haveinvented certain new and useful Improvements in Mainsprings for lVatches5 and I do declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertains to make and use the same. My invention hasrelation to improvements in main springs for time pieces, music boxes,mechanical toys, and other devices in which a spring is employed as amotor, and it has for its several objects to prevent overwindin g of thespring and thereby overcome and reduce the liability of breakage; toobtain a more equal tension and an invariable pressure from the timethat the spring is wound up until it is run down; to distribute pressurethroughout the spring while the same is being wound up; and to preventacute bending of the inner coils when the watch is wound u p.

With the foregoing ends in View the novelty of the invention will befully understood from the following description and claims when taken inconnection with the annexed drawings in which Figure l, is a plan Viewof a watch barrel, the cap being removed to permit of a betterillustration of the spring. Fig. 2, is a diametrical section of thesame. Fig. 3, is a perspective View, illustrating the relative positionof the friction spring for preventing overwinding to the mainspring towhich said friction spring is connected as shown. Fig. 4, is aperspective view of the shell removed, and Fig. 5, is a detail plan viewillustrating the position of the friction spring to the main springbefore the said main spring is wound In the said drawings similarletters designate corresponding parts throughout the several viewsreferring to which:

A, indicates the barrel of a watch or the like which may be of theordinary or any approved construction; and B, indicates the arbor havingthe enlarged portion I), provided with the shoulder c, and a lug or studd.

C, indicates the main spring proper, which may be of the ordinary or anyapproved construct-ion; and D, indicates the stay spring which is formedintegral with or is connected to the inner end of the main spring,within the coil, at about the point e, in Fig. l, of the drawings. Thisshort stay spring D, which is of a lower temper than the main spring C,and is bent upon itself so as to be against the inner whirl of said mainspring, bears against the shoulder o, of the enlarged portion b, ot thearbor, and is provided with a suitable aperture for the engagement ofthelug` or stud d, of the said enlarged portion b. The stay spring D, isnot only of a lower temper, but it is of an approximately doublethickness and strength with respect to the main spring, whereby it willbe seen that said stay spring will at once give the timepiece or otherdevice the proper motion when the main spring is the least wound; andthe pressure of the said stay spring against the main spring is amplysufiic-ient to force the pressure outward throughout the main spring, byvirtue of which acute bending and consequent breakage of the innerwhirls or coils will be prevented. By the provision of the stay springit will be further seen that when the main spring is wound up the innercoils thereof will be the last to wind, andwill be prevented fromapproaching too close to the arbor, so as to leave a space about saidarbor and prevent the acute bending before mentioned, the size of suchspace about the arborbeing governed by the thickness, temper, and lengthof the stay spring.

As better illustrated in Fig. l, of the drawings, the stay spring D, istapered for a portion of its length adjacent to its free end so that themain spring proper willbe permitted to coil symmetrically and will beprevented from bulging or the like. Inasmuch as by the provision of thestay spring D, the outer coils of the main spring are wound before theinner coils, the force or pressure will iirst be from the outside of thecoil toward the center thereof, and when the central portion of thespring is wound, there will also be a pressure from the center of thecoil toward the outside thereof or in other words there will IOO be apressure or brace on each side of each coilwhich will overcome acuteandquick bending and will consequently prevent breakage.

M, indicates a friction spring which is designed and adapted to hold theouter end of the main spring while the same is being wound and to moveand permit a movement of the main spring when the same has beencompletely wound so as to prevent overwindingand consequent breakage ofthe said main spring. This friction spring M, is of such a thickness andtemper that it will bind against the shell (presently described,) and byfrictional contact with said shell will hold the spring until the sameis completely wound up; and the said friction spring which is riveted orotherwise connected to the main spring, is provided with a tongue w,which extends forward of the end of the main spring and is reduced inwidth so as to render it more resiln ient for a purpose presently setforth. The end of the friction spring M, opposite to the tongue w, ispreferably beveled in practice so as to better adapt it to take betweenthe end of the main spring and the friction spring after it has beenpassed around said main spring as better shown in Fig. 3, of thedrawings.

N, indicates a shell which is preferably formed from steel and isdesigned and adapted to be placed within the barrel and to inclose themain spring and friction spring whereby it will prevent an expansion ofthe brass barrel by the action of the friction spring. This barrel N, asbetter shown in Fig. 4f, of the drawings, is provided at inter- Vals inits length with apertures or slots u, into one of which the tongue fw,of the friction spring takes as soon as said friction spring movesaround after the main spring` is wound up; the click of the tongue inentering the aperture or slot being designed to notify the personwinding the watch that the spring has been completely wound. Thefriction spring being moved in the direction of the arrow, shown in Fig.3, it will be seen that if the winding is continued after the tonguetakes into one of the apertures or slots of the shell, the tongue willtake out of Ithe aperture and slot and move upon the inside of the shelluntil it reaches the next aperture or slot, and so on, whereby it willbe seen that the arbor may be turned for an indefinite period of timewithout damage to the spring.

In the practice of myinvention I do not desire to confine myself todetails in construction, as I reserve the right to make such changes ormodifications as fairly fall within the scope or spirit of my invention.

Having described my invention, what I claim, and desire to secure byLetters Patent, 1s-

1. A main spring for time pieces, music boxes and the like having a stayspring at its inner end, substantially as and for the pur= pose setforth.

2. A main spring for time pieces, music boxes and the like having a stayspring at its inner end; the said stay spring being bent upon itself toengage an arbor and bear against the inner coil of the main spring,substantially as and for the purpose set forth.

A main spring for time pieces, music boxes and the like, having a stayspringl at its inner end; the said stay spring being bent upon itself toengage the arbor and bear against the inner coil of the main springandhaving its free portion tapered, substantially as and for the purposeset forth.

4. A main spring for time pieces, music boxes and the like having a stayspring at its inner end; the said stay spring being of a lower temperanda greater strength than the said main spring,substantially as and forthe purpose set forth.

5. In a barrel for time pieces, music boxes and the like, thecombination with an arbor having the enlarged portion provided with ashoulder and a lug or stud; of a main spring, and a stay spring at theinner end of said main spring; the said stay spring being bent uponitself to engage the shoulder and lug or stud of the enlarged portion ofthe arbor, substantially as and for the purpose specified.

G. The combination of an inclosing shell having an aperture, anda mainspring arranged within the shell and having a friction spring at itsouter end; the said friction spring having one of its ends extendedforward of the outer end of the main spring to engage the aperture ofthe inclosing shell, and being adapted to bind and hold the main springwhile the same is being wound and to move with said main spring if thearbor is turned after the completion of the winding, substantially asand for the purpose set forth.

7. A main spring for time pieces, music boxes and the like having afriction spring at its outer end; the said friction spring being adaptedto bind and hold the main spring while the same is being wound and. tomove with said main spring if the arbor is turned after the completionof the winding, and having one of its ends extended forward of the outerend of the main spring and reduced in width so as to engage an aperturein an inclosing shell, substantially as and for the purpose set forth.

S. Ina barrel for time pieces, music boxes and the like, the combinationwith a shell adapted to be placed within the barrel and having a slot oraperture; of a main spring having a friction spring at its outer end;the said friction spring having one of its ends extended forward of theend of the main spring and adapted to en gage the slot or aperture inthe shell, substantially as and for the purpose set forth.

9. In a barrel for time pieces, music boxes and the like, thecombination with a spring; of a steel shell placed. within the barrel soas to surround the spring and prevent the same IOC rgo

from expanding the barrel, substantially as specified.

l0. Ina barrel for time pieces, music boxes and the like, thecombination with the main spring and a shell arranged Within the barreland having an aperture; of a friction spring connected to the mainspring and having a resilient tongue adapted to engage the aperture inthe shell, substantially as specified.

11. In a barrel for time pieces, music boxes and the like, thecombination with a main spring having a stay spring at its inner endanda friction spring atits outer end 3 the said friction spring beingadapted to surround the JOHN B. JOBSON.

lVitnesses:

C. W. LEONARD, J. Sn BUDD.

